February 24, 2014
thefurioustenderness asked: Hello, I have a couple of questions about glyoxal. First, does the diluted glyoxal solution that you use for hardening need to be thrown away after each use, or can it be kept and reused? If it needs to be thrown out, is there a special way to discard it or is it ok to pour down the drain? Second, I have read reports of glyoxal causing yellowing of the paper. Has this been an issue for you? Thank you for your time!
I tend to mix up new glyoxal solution each time I harden although I believe my students have reused the same solution over the course of a few weeks before discarding–I pour the used glyoxal solution down the drain where I teach. There is a neutralizing tank built into our liquid waste system that treats all the chemicals we discard (except for Fixer-we have a separate liquid waste disposal service for the Fixer). I’ve been using glyoxal for over ten years and have not experienced it yellowing the paper. Formaldehyde was used when I first learned gum printing in the 80’s but recently the FDA determined it to be a carcinogen and has since banned the use of the chemical. Hope this helps. Tony
